1. Field of the Invention
The present invention relates to ophthalmic lenses, and more particularly to contact lenses incorporating features that enhance the eye and surrounding structures.
2. Discussion of the Related Art
Myopia or nearsightedness is an optical or refractive defect of the eye wherein rays of light from an image focus to a point before they reach the retina. Myopia generally occurs because the eyeball or globe is too long or the cornea is too steep. A minus powered spherical lens may be utilized to correct myopia. Hyperopia or farsightedness is an optical or refractive defect of the eye wherein rays of light from an image focus to a point after they reach or behind the retina. Hyperopia generally occurs because the eyeball or globe is too short or the cornea is too flat. A plus powered spherical lens may be utilized to correct hyperopia. Astigmatism is an optical or refractive defect in which an individual's vision is blurred due to the inability of the eye to focus a point object into a focused image on the retina. Unlike myopia and/or hyperopia, astigmatism has nothing do to with globe size or cornea steepness, but rather it is caused by an abnormal curvature of the cornea. A perfect cornea is spherical whereas in an individual with astigmatism, the cornea is not spherical. In other words, the cornea is actually more curved or steeper in one direction than another, thereby causing an image to be stretched out rather than focused to a point. A cylindrical lens rather than a spherical lens may be utilized to resolve astigmatism.
Contact lenses may be utilized to correct myopia, hyperopia, astigmatism as well as other visual acuity defects. Contact lenses may also be utilized to enhance the natural appearance of the wearer's eyes. In other words, contact lenses may be colored or tinted to provide a variety of effects to the appearance of the eye. A number of different types of tinted contact lenses are currently available to enhance an individual's eye color or change it altogether. Contact lenses comprising cosmetic enhancement tints are designed to enhance ones natural eye color and are best suited for light-colored eyes such as blues, greens, hazels and grays. Contact lenses comprising opaque tints are designed to change the color of dark eyes. These lenses are patterned and are designed to cover the iris while providing a natural look. Contact lenses may also comprise visibility tints which are designed to make the lens visible during handling with no discernible effect on eye color.
The use of tinted or colored contact lenses to alter or enhance the natural color of the iris is well known. In manufacturing conventional tinted contact lenses, it is known to use either or both translucent and opaque colors in one layers of color with the object of creating a natural appearing tinted iris. Typically, the color layers are each applied at a single thickness. This provides color variation only with the use of multiple colors or points at which the translucent color overlaps another color layer. However, the natural iris is composed of a large number of different colors and color combinations intermixed to create color variations. The relatively small number of colors and color layers that may be utilized in producing tinted contact lenses limits the designer's ability to create a natural appearing lens. Accordingly, it would be advantageous to create eye color enhancement above and beyond simply altering the color of the iris.